1. Field of the Invention
The present invention relates to irrigation control systems, and in particular to irrigation control systems that collect irrigation data from one or more sensors.
2. Description of the Related Technology
Irrigation systems are used widely in commercial and residential applications. Typical irrigation systems include an irrigation controller connected to one or more irrigation devices (e.g., valves) which provide water to desired locations via an assortment of hydraulic components (e.g., pipes, sprinkler heads, and drip lines). The irrigation controllers control the components to provide desired irrigation in accordance with a programmed schedule.
With some irrigation control systems, an operator determines the amount of water and the time at which the water should be applied by defining an irrigation schedule. The irrigation schedule may determine which valves are activated at which times, and for how long. Any changes to the irrigation schedule may be performed manually by the operator.
Other so called “smart” irrigation control systems receive input from sensors that indicate the nature of the environment being irrigated. This input may be used by the irrigation controller to determine how much irrigation is necessary in order to maintain the health of the installed plant life. For example, if the sensor input indicates there has been a recent rain storm, it may not be necessary to provide additional water via the irrigation system. Other input received by the irrigation controller may indicate the moisture present in the soil. Upon receiving the indication of soil moisture, the irrigation controller may determine an amount of irrigation needed to maintain soil moisture levels within a desired range that supports the installed plant life.
Other irrigation sensors may provide input on the flow rate of water through an irrigation supply line. By knowing the actual flow rate of the water, an irrigation controller may more precisely calculate the amount of water being applied during an irrigation program. Based on the needs of the installed plant life, the irrigation controller may extend or shorten the time a particular irrigation zone is active based on the flow rate of the water in the zone.
Irrigation controllers may collect data from these irrigation sensors via either wireless or wired connections. In some environments, wireless connections may have distance limitations, and so a wired connection may be favored. With existing irrigation controller solutions, use of wired sensors requires a dedicated wiring circuit for each sensor. In an irrigation zone including, for example, three sensors, three separate wiring circuits may be needed between the irrigation controller and the sensors in that irrigation zone. An irrigation zone may also include at least one valve actuator. The valve actuation may be performed by an electrical solenoid. A separate wired circuit between the irrigation controller and the solenoid may also be necessary. In such a configuration, four individual sets of wired connections may be needed for one irrigation zone. When one irrigation installation may include up to hundreds of individual zones, the need to provide a dedicated wiring circuit for each irrigation sensor and each water valve may be problematic. For example, when installing a new irrigation system, the need to possibly quadruple the number of wiring circuits necessary to install a smart irrigation system may add significant cost to the installation. Furthermore, when retrofitting legacy systems with smart irrigation controllers that utilize irrigation sensors, the need to install additional wiring may disrupt established ground cover. Additionally, the expense of installing additional wiring may be a significant proportion of the retrofitting cost, and may reduce adoption of smart irrigation systems when not required by law.